feat: collapsible tool lines in terminal

Long tool messages (e.g. Bash commands) are now stored in full and
displayed collapsed by default, with a toggle button to expand/collapse.
Removes backend truncation of Bash commands at 50 chars.

src/lib/components/Terminal.svelte

@@ -1,6 +1,7 @@
 <script lang="ts">
   import { claudeStore, type TerminalLine } from "$lib/stores/claude";
   import { afterUpdate, tick, onMount, onDestroy } from "svelte";
+
   import ConversationTabs from "./ConversationTabs.svelte";
   import Markdown from "./Markdown.svelte";
   import HighlightedText from "./HighlightedText.svelte";
@@ -187,6 +188,22 @@
       copiedMessageId = null;
     }, 2000);
   }
+
+  // Collapsible tool lines
+  const TOOL_COLLAPSE_THRESHOLD = 60;
+  let expandedToolLines: Record<string, boolean> = {};
+
+  function isToolContentLong(content: string): boolean {
+    return content.length > TOOL_COLLAPSE_THRESHOLD;
+  }
+
+  function truncateToolContent(content: string): string {
+    return content.slice(0, TOOL_COLLAPSE_THRESHOLD) + "…";
+  }
+
+  function toggleToolLine(id: string) {
+    expandedToolLines = { ...expandedToolLines, [id]: !expandedToolLines[id] };
+  }
 </script>
 
 <div
@@ -289,6 +306,22 @@
                   <span class="copy-text">{copiedMessageId === line.id ? "Copied!" : "Copy"}</span>
                 </button>
               </div>
+            {:else if line.type === "tool" && isToolContentLong(maskPaths(line.content, hidePaths))}
+              <span class="tool-collapsible">
+                <HighlightedText
+                  content={expandedToolLines[line.id]
+                    ? maskPaths(line.content, hidePaths)
+                    : truncateToolContent(maskPaths(line.content, hidePaths))}
+                  searchQuery={currentSearchQuery}
+                />
+                <button
+                  class="tool-toggle-btn"
+                  onclick={() => toggleToolLine(line.id)}
+                  title={expandedToolLines[line.id] ? "Collapse" : "Expand to see full content"}
+                >
+                  {expandedToolLines[line.id] ? "▲" : "▼"}
+                </button>
+              </span>
             {:else}
               <HighlightedText
                 content={maskPaths(line.content, hidePaths)}
@@ -408,4 +441,28 @@
   .terminal-line {
     position: relative;
   }
+
+  .tool-collapsible {
+    display: inline-flex;
+    align-items: baseline;
+    gap: 0.4em;
+  }
+
+  .tool-toggle-btn {
+    background: none;
+    border: none;
+    color: var(--text-tertiary, #6b7280);
+    cursor: pointer;
+    font-size: 0.7em;
+    padding: 0;
+    line-height: 1;
+    opacity: 0.7;
+    transition: opacity 0.15s ease;
+    font-family: inherit;
+  }
+
+  .tool-toggle-btn:hover {
+    opacity: 1;
+    color: var(--terminal-tool, #c084fc);
+  }
 </style>